Chris Ashton will miss England's opening match of their autumn international series against Fiji later this month after being handed a one-week ban by the Rugby Football Union on Wednesday night.

The Saracens wing received a retrospective yellow card for a dangerous tackle at his former club Northampton, taking him to three for the season and triggering an automatic disciplinary hearing.

Ashton appeared before a disciplinary panel in London on Wednesday night and escaped with the minimum punishment, even though he could have been given a two game ban considering his disciplinary record.

He would have been in line for a month's suspension had he been cited for the feet and shoulder challenge on his opposite number Vasily Artemyev, but the Northampton director of rugby, Jim Mallinder, said after the match that he did not feel the action merited a red card. Ashton, who was penalised by the referee, Andrew Small, said the challenge was down to bad timing.

Ashton received a yellow card in the opening match of the season against London Irish at Twickenham, his debut for Saracens, for a late tackle on Steve Shingler and was sent to the sin-bin at Exeter in the fourth round after shoulder-barging his way into a maul.

The danger for Ashton is that the three-man panel, which is chaired by the Rugby Football Union's chief disciplinary officer, Jeff Blackett, decides that his disciplinary record merits more than a one-match ban. He was suspended for four weeks last season for unsportsmanlike behaviour after pulling the hair of the Leicester wing Alesana Tuilagi. His three sin-bins have been for challenges that veered between the reckless and the dangerous and he will be warned about his future behaviour.

Any ban for Ashton would not include Sunday's match between Saracens and Wasps as he has not been released for it by England.

Gloucester's Charlie Sharples will be the beneficiary of Ashton's actions. With Ugo Monye, he is the only specialist wing in the England squad – Ben Foden, who played on the left wing during the summer tour to South Africa, is injured – and with the centre Jonathan Joseph likely to miss at least the first half of the autumn series because of an ankle injury, the England head coach, Stuart Lancaster, has a shortage of options in the three-quarters.

Lancaster has other injury concerns, not least in his front row where the hooker Dylan Hartley has a knee injury that will rule him out of at least the first two matches and the prop Joe Marler has not trained this week because of a tight hamstring.

In addition, the second row Courtney Lawes will not be available for the start of the series because of a knee injury that he, like Hartley, sustained during Northampton's defeat by Saracens last Saturday.

Meanwhile, Kelly Brown has been named as Scotland's captain for their autumn Test against New Zealand, the head coach Andy Robinson has confirmed. The 30-year-old Saracens back-row forward succeeds the Edinburgh hooker Ross Ford, and will lead the team out on the occasion of his 50th cap against the world champions on 11 November.

Brown was in line for the role before a broken ankle forced him to miss this year's ill-fated Six Nations and the successful summer tour to Australia, Fiji and Samoa as Ford led the side throughout. Now the former Glasgow Warriors player, who can play No8 or blindside flanker, will become Scotland's fifth captain in two years.

"It's a huge honour and I'm really looking forward to the challenges ahead," said Brown. "It's been so long since I've actually played for Scotland [September 2011], so I'm really looking forward to that."

Robinson added: "Kelly Brown is an inspirational person. He has an aura, confidence and belief about him and a firm understanding of the game. He has been a very consistent performer for Scotland. It's because of these qualities that he has been appointed Scotland captain."